Ladder jack



D 6, 1950 2. J. JAGIEL 2,535,291

LADDER JACK Filed- NOV. 14, 1945 3mm I ZIGMAN JJAGIEL 22M; @wfgzm Patented Dec. 26, 1950 UNITED STATES PATENT OFFICE Application November 1 Claim.

This invention relates to ladder jacks, and has for its primary object to provide a simple and efiicient device to support scaffolding or staging which may be applied to any ladder regardless of size, rung spacing, upright spacing or other variables.

Another object of the invention is to provide a device which is safe to use and which adapts itself to easy adjustment to maintain a horizontal scalfold position.

Other objects and advantages of the invention will be apparent from the following specification, reference being had to the accompanying drawings, in which Fig. 1 is a perspective view of a pair of ladder jacks constructed in accordance with the invention disposed in operating position on a ladder; Fig. 2 is a top plan view of one of the pair of jacks, and Fig. 3 is a side elevation of the device shown in Fig. 2.

Referring to the drawings, the present invention is shown applied to a ladder i d and supporting a scaffold board H2. The drawings show only one position of use of the ladder jacks but it should be understood that other common uses are easily made. For example, the scaffolding may be supported inside the ladder, as Well as in the outside position shown, double scaffolding is easily possible with the application of two pairs of jacks to the same ladder, as Well as all other of the numerous uses to which these devices are commonly put by the trade. structurally, there is no variation so that description of the jack itself serves as a disclosure of its various functions.

1945, Serial No. 628,549

The jacks are used in pairs, each member of which comprises an upper support I4 having a ladder engaging yoke it at one end. At its outer end the support I4 is pivotally connected to a brace I8 which extends, when used as shown, inwardly and downwardly to be supported at its lower end by a hook 29 extending around the ladder upright. The brace i8 is preferably made with a rectangular end that extends slightly above the plane of the associated support I 4 to present an obstruction to lateral displacement of the scalfold board I 2, so that the board cannot slip 01f the support but must be lifted therefrom when the brace is in its operating pos tion.

Connection between the hook 20 and the brace I8 is made at one end of the hook so that the downward thrust of the brace cants the hook into a firm, binding engagement with the ladder upright. As the load on the brace increases the binding force also increases so that the danger of slipping or movement of the hook is reduced. It Will be seen that, by reason of the canting, binding engagement of the hook with the ladder upright, the jack is readily adjustable to maintain a horizontal position of the support M with- 6 out in any way changing the efiective length of the brace or of the support since the hook 20 may be passed around any portion of the ladder upright and operates entirely independently of the ladder rungs. Since the jack is supported without reference to the ladder rungs, its position may be readily changed and the safety factor is increased.

For ease of operation and application, the hook 29 is made detachable, being threaded on its long arm 2| to receive a wing nut 22 after passing through a suitable hole in the brace !3. In practice, the Wing nut may be used to establish a lateral stability in the scaffold by drawing the brace 18 against the ladder upright, although this precaution is not entirely necessary.

In order that the jack may be entirely demounted, the pivotal connection between the brace 18 and support M may also be a bolt and wing nut connection so that the entire jack may be disassembled and easily carried or packed.

In operation, one of the pairs is applied to a ladder with the yoke around the ladder upright and the hook 20 put in position such that the plane of the support I4 is substantially horizontal. Subsequently, it is only necessary to place the staging board, and the device is then ready for use although, if desired, the wing nuts 22 may be tightened to increase the stability of the entire assembly.

I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claim.

What I claim is:

A ladder jack comprising a support, a yoke formed at one end of said support to engage a ladder upright, a brace for said support, and a hook means connected to said brace and having binding engagement with said ladder upright, the connection between said hook means and said brace being adjacent one side of the ladder upright whereby the b nding engagement of said hook is caused as a reacton to the forces in said brace, and means formed on said hook to draw said brace against a ladder upright for lateral stability.

ZIGMAN J. JAGIEL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 569,645 Jones c. Oct. 20, 1896 765,817 Cox July 26, 1904 1,143,678 Winans June 22, 1915 1,305,922 Moller June '3, 1919 1,477,738 White Dec. 18, 1923 

